One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when it's a good idea to plant penstemon is to refer to the USDA zone info for Boonton.

Planting Calendar for Penstemon

Frost tolerance for penstemon:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Penstemon tend to make it in mild cold which means that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Boonton is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant penstemon and expect a good harvest is probably September. You probably don't want to wait any later than that or else your penstemon may not have a chance to grow to maturity. Starting your penstemon indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Boonton. In the coldest months of winter you can expect an average low temperature of -5°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Boonton and it can change quite a bit from year to year. Half of the time in Boonton you get a frost after April 15 so always be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Boonton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Boonton

You may be interested in your other planting guides for Boonton.